[Devel] [PATCH 3/6] proc connector: proc listeners helpers added

[Stanislav Kinsburskiy]

These are precursor helpers, which will hide all the containerization magic.

Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
---
 drivers/connector/cn_proc.c |   57 +++++++++++++++++++++++++++++++++----------
 1 file changed, 44 insertions(+), 13 deletions(-)

diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index dcd993e..5fc1105 100644
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -66,6 +66,28 @@ static inline void get_seq(__u32 *ts, int *cpu)
 	preempt_enable();
 }
 
+static int get_listeners(struct net *net)
+{
+	return atomic_read(&proc_event_num_listeners);
+}
+
+static void inc_listeners(struct net *net)
+{
+	atomic_inc(&proc_event_num_listeners);
+}
+
+static void dec_listeners(struct net *net)
+{
+	atomic_dec(&proc_event_num_listeners);
+}
+
+static struct net *task_net(struct task_struct *task)
+{
+	if (task->nsproxy && task->nsproxy->net_ns)
+		return task->nsproxy->net_ns;
+	return &init_net;
+}
+
 void proc_fork_connector(struct task_struct *task)
 {
 	struct cn_msg *msg;
@@ -73,8 +95,9 @@ void proc_fork_connector(struct task_struct *task)
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 	struct timespec ts;
 	struct task_struct *parent;
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -106,8 +129,9 @@ void proc_exec_connector(struct task_struct *task)
 	struct proc_event *ev;
 	struct timespec ts;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -134,8 +158,9 @@ void proc_id_connector(struct task_struct *task, int which_id)
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 	struct timespec ts;
 	const struct cred *cred;
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -174,8 +199,9 @@ void proc_sid_connector(struct task_struct *task)
 	struct proc_event *ev;
 	struct timespec ts;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -201,8 +227,9 @@ void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
 	struct proc_event *ev;
 	struct timespec ts;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -236,8 +263,9 @@ void proc_comm_connector(struct task_struct *task)
 	struct proc_event *ev;
 	struct timespec ts;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -264,8 +292,9 @@ void proc_coredump_connector(struct task_struct *task)
 	struct proc_event *ev;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 	struct timespec ts;
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -291,8 +320,9 @@ void proc_exit_connector(struct task_struct *task)
 	struct proc_event *ev;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 	struct timespec ts;
+	struct net *net = task_net(task);
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -322,14 +352,14 @@ void proc_exit_connector(struct task_struct *task)
  * values because it's not being returned via syscall return
  * mechanisms.
  */
-static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
+static void cn_proc_ack(struct net *net, int err, int rcvd_seq, int rcvd_ack)
 {
 	struct cn_msg *msg;
 	struct proc_event *ev;
 	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 	struct timespec ts;
 
-	if (atomic_read(&proc_event_num_listeners) < 1)
+	if (get_listeners(net) < 1)
 		return;
 
 	msg = buffer_to_cn_msg(buffer);
@@ -357,6 +387,7 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
 {
 	enum proc_cn_mcast_op *mc_op = NULL;
 	int err = 0;
+	struct net *net = nsp->sk->sk_net;
 
 	if (msg->len != sizeof(*mc_op))
 		return;
@@ -379,10 +410,10 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
 	mc_op = (enum proc_cn_mcast_op *)msg->data;
 	switch (*mc_op) {
 	case PROC_CN_MCAST_LISTEN:
-		atomic_inc(&proc_event_num_listeners);
+		inc_listeners(net);
 		break;
 	case PROC_CN_MCAST_IGNORE:
-		atomic_dec(&proc_event_num_listeners);
+		dec_listeners(net);
 		break;
 	default:
 		err = EINVAL;
@@ -390,7 +421,7 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
 	}
 
 out:
-	cn_proc_ack(err, msg->seq, msg->ack);
+	cn_proc_ack(net, err, msg->seq, msg->ack);
 }
 
 int __net_init cn_proc_init_net(struct net *net)